import java.util.Arrays;
public class Test04{
    public static void main(String[] args){
            int[] arr = {1,2,3};
            arr = expand(arr);
            System.out.println(Arrays.toString(arr));

    }
    public static int[] expand(int[] arr){
        int new_arr[] = new int[arr.length * 2];
        System.arraycopy(arr ,0 ,new_arr ,0 ,arr.length);
        return new_arr;
    }
}